Modeling of material constitutive behavior in a variety of applications is important. The conventional tension or compression tests are only applicable under low strain-rates (10−3-10−1/s) and low temperatures. The accuracy of this method strongly depends on the models of chip formation and tool-chip friction. In the machining processes, chip deformation, material constitutive relationships, and tool-chip friction are coupled together and affect each other. In most of analytical models of chip formation, it is customary to calculate the strain-rate in the primary shear zone by assuming the thickness ΔS of this zone to be one-tenth of the undeformed chip thickness. ΔS and strain-rates also highly depend on the tool edge roundness, i.e., the tool edge radius, the position of stagnation point on the rounded cutting edge, and tool-chip friction. The effect of tool edge roundness is neglected in the parallel-sided shear zone model.
Thus, it would be an advancement in the art to provide a new slip-line model of chip formation for machining, taking into account the effects of tool edge roundness on ΔS and strain-rates. Discussed herein is a methodology for modeling material constitutive behavior at large strains, high strain-rates, and elevated temperatures through an orthogonal machining test.